Preparation method and application of ammonium thiocyanate modified activated carbon

Abstract

The invention discloses a preparation method and an application of ammonium thiocyanate modified activated carbon, and belongs to the field of wet metallurgy and precious metal recycling. According tothe method, an activated carbon material serves as a substrate, ammonium thiocyanate serves as a modified agent, and a modified activated carbon material is prepared under a certain condition. Functional groups containing atoms such as nitrogen, oxygen and sulfur are introduced on the surface of the activated carbon, so that surface properties of the material are changed, and [Au(S203)2]3-complexions in thiosulfate gold leaching solution are effectively adsorbed. The method overcomes the shortcomings that a current Prussian blue analogue compound modified activated carbon preparation processis complicated and unstable in product structure performance, 2-mercaptobenzothiazole modified activated carbon adopts expensive modified agents, toxic organic solvents and the like, and the method has the advantages of simple preparation method, low cost, environmental friendliness and the like.

Description

technical field [0001] The invention relates to a preparation method and application of activated carbon modified by ammonium thiocyanate, and belongs to the fields of hydrometallurgy and precious metal recovery. Background technique [0002] Because of its unique physical and chemical properties, gold plays a pivotal role in human production and life. Cyanide method has always been the main gold leaching technology for gold extraction, but highly toxic cyanide is easy to leak, and if it is not handled properly, it will cause serious damage to the environment and ecology. Therefore, non-cyanide gold extraction technology can be developed. Among them, thiosulfate gold extraction technology is non-toxic, less polluting, low cost, high reaction selectivity, low corrosiveness of leaching solution and easy to handle carbonaceous gold ore, copper-containing gold ore and The advantages of complex sulfur-containing gold ore are considered to be the most promising non-cyanide gold ...

AI Technical Summary

Problems solved by technology

However, in the thiosulfate gold extraction process, the activated carbon on [Au(S 2 o 3 ) 2 ] 3- The adsorption capacity of complex ions is extremely low, which may be due to the large volume, high charge and low affinity of gold thiosulfate complex ions to activated carbon, resulting in difficult adsorption.

[0003] In order to overcome the shortcoming of the low loading capacity of activated carbon, someone adds 1-2 times the amount of cyanide in the thiosulfate gold leaching solution, and [Au(S 2 o 3 ) 2 ] 3- Convert to [Au(CN) 2 ] - It can be effectively adsorbed by activated carbon. Although the effect of this method is good, it cannot avoid the highly toxic CN - Pollution

Patent CN 104549147 A loads Prussian blue-like compounds on the surface of activated carbon. Although some results have been achieved, the modification process is to deposit copper ferrocyanide on the surface of activated carbon, which is a physical modification and the modification process is complicated and has poor stability. Difficult to reproduce, not conducive to production

Patent CN 107215872 A adopts the impregnation method to load 2-mercaptobenzothiazole on the activated carbon, which has a better adsorption effect on gold, but this method needs to use expensive modifiers and toxic organic solvents; in addition, the strong alkali solution will destroy the active carbon. Porous structure, resulting in reduced adsorption capacity